Jason Cornish faces up to 10 years in prison and fines of up to $250,000

A former IT employee at the U.S. subsidiary of Japanese drug maker Shionogi has been arrested after crippling the company's computer infrastructure for revenge.

Jason Cornish, 37, of Smyrna, Georgia, was an information technology employee at Shionogi up until he resigned in September 2010. According to reports, he resigned because of company layoffs that would affect his former supervisor and a close friend.

On February 3, 2011, Cornish went to a Smyrna McDonald's during the early morning hours and gained unauthorized access to Shionogi's computer network. He did so by using a Shionogi user account to access a Shionogi server, and then used software he quietly installed on the server weeks earlier at his home.

Cornish then deleted the contents of 15 VMware hosts, which were used to run "the equivalent of 88 servers." By deleting these hosts, Cornish affected the company's order tracking system, financial management software and email and BlackBerry servers.

The company's business operations froze for days, costing Shionogi approximately $800,000.

"The Feb. 3 attack effectively froze Shionogi's operations for a number of days, leaving company employees unable to ship product, to cut checks or even to communicate via email," said the U.S. Department of Justice in court filings.

The FBI's Cyber Crimes Task Force was able to find that the attack originated from a computer connected to the Smyrna McDonald's wireless network. It also found that Cornish had used his credit card to make a purchase at that very same McDonald's the morning of the attack. In July 2011, Cornish was arrested near his Smyrna home by FBI agents.

Cornish plead guilty to the computer intrusion charges on Tuesday, and faces up to 10 years in prison and fines of up to $250,000. His sentencing is scheduled for November 10.

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